Family sharing in Windows 10 doesn't work with Minecraft Dungeons, which I have purchased twice (for both Xbox One X and Windows 10) using my Microsoft-account. Right now, my kids are playing the game on Xbox using their own profiles, but they're not able to play the game on Windows.

Here's what I have observed:

1. When using the local Windows account which was used to purchase the game, signing into one of the "family sharing" enabled Microsoft accounts when launching the game on Windows, results in a notification stating that "you're signed into this game on another device...", but clicking the "sign in here" button results in a new notification stating that "game ownership not established... you don't appear to own Minecraft Dungeons on this account".
2. When using one of my kids' local Windows accounts (which are linked to their Microsoft accounts), on which we have also downloaded the game from the Microsoft store, attempting to launch the game results in a Windows alert stating that "no applicable app licenses found".
3. If my profile is used to play the game on the Xbox, it's not possible to play the game using the same profile on Windows (even though the game has been purchased twice).
4. There is no problem running the game on Xbox with "family sharing" enabled accounts.